Activity is not assigned to Android.app.Activity Manifest XML

java android android-activity manifest

16,894

Solution 1

Firstly, you only declare activities in manifest file, not fragments. So remove this line from manifest file

<activity
        android:name=".FeedbackMain"
        android:label="@string/title_activity_feedback_main" >
    </activity>

Secondly, if you want to use actionbar, you class should extend ActionBarActivity not FragmentActivity. so change your mainactivity from

public class MainActivity extends FragmentActivity {

public class MainActivity extends ActionBarActivity{

then make sure you call getSupportActionBar() if you are using support library

EDIT:

ActionBar.TabListener tabListener = new ActionBar.TabListener() { 
@Override 
public void onTabReselected( 
android.support.v7.app.ActionBar.Tab arg0, 
FragmentTransaction arg1) { 
// TODO Auto-generated method stub 

} 

@Override 
public void onTabSelected( 
android.support.v7.app.ActionBar.Tab arg0, 
FragmentTransaction arg1) { 
// TODO Auto-generated method stub 

} 

@Override 
public void onTabUnselected( 
android.support.v7.app.ActionBar.Tab arg0, 
FragmentTransaction arg1) { 
// TODO Auto-generated method stub 

} 
};

Solution 2

this error is caused because FeedBackMain is declared as Activity not as a Fragment

 <activity
        android:name=".FeedbackMain"
        android:label="@string/title_activity_feedback_main" >
    </activity>

if you really want use it as Activity Change

public class FeedbackMain extends Fragment {

public class FeedbackMain extends FragmentActivity {

but if you want use it as Fragment just delete the declaration inside your AndroidManifest.xml

use actionBar = getSupportActionBar(); instead of getActionBar()

You need some method implementations:

actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
ActionBar.TabListener tabListener = new ActionBar.TabListener() {

    public void onTabReselected(android.app.ActionBar.Tab tab,
                                android.app.FragmentTransaction ft) {
    }

    public void onTabSelected(android.app.ActionBar.Tab tab,
                              android.app.FragmentTransaction ft) {
        // on tab selected show respected fragment view
        Tab.setCurrentItem(tab.getPosition());
    }


    public void onTabUnselected(android.app.ActionBar.Tab tab,
                                android.app.FragmentTransaction ft) {
    }

    @Override
    public void onTabReselected(
            android.support.v7.app.ActionBar.Tab arg0,
            FragmentTransaction arg1) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onTabSelected(
            android.support.v7.app.ActionBar.Tab arg0,
            FragmentTransaction arg1) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onTabUnselected(
            android.support.v7.app.ActionBar.Tab arg0,
            FragmentTransaction arg1) {
        // TODO Auto-generated method stub

    }
};

16,894

Author by

QWERTY

Updated on June 09, 2022

Comments

QWERTY almost 2 years

I am having some trouble with the fragment in Android Studio. So basically this is my MainActivity:

public class MainActivity extends FragmentActivity {
final Context context = this;

ViewPager Tab;
TabPagerAdapter TabAdapter;
ActionBar actionBar;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TabAdapter = new TabPagerAdapter(getSupportFragmentManager());
    Tab = (ViewPager) findViewById(R.id.pager);
    Tab.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            actionBar = getActionBar();
            actionBar.setSelectedNavigationItem(position);
        }
    });
    Tab.setAdapter(TabAdapter);
    actionBar = getActionBar();
    // Enable Tabs on Action Bar
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    ActionBar.TabListener tabListener = new ActionBar.TabListener() {
        @Override
        public void onTabReselected(android.app.ActionBar.Tab tab,
                                    android.app.FragmentTransaction ft) {
        }

        @Override
        public void onTabSelected(android.app.ActionBar.Tab tab,
                                  android.app.FragmentTransaction ft) {
            // on tab selected show respected fragment view
            Tab.setCurrentItem(tab.getPosition());
        }

        @Override
        public void onTabUnselected(android.app.ActionBar.Tab tab,
                                    android.app.FragmentTransaction ft) {
        }
    };

    // Add New Tab
    actionBar.addTab(actionBar.newTab().setText("Feedback")
            .setTabListener(tabListener));
    actionBar.addTab(actionBar.newTab().setText("History Log")
            .setTabListener(tabListener));


}
}

And then my another class which is one of the tab code:

public class FeedbackMain extends Fragment {
View feedbackMainView;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    feedbackMainView = inflater.inflate(R.layout.activity_feedback_main,
            container, false);

    return feedbackMainView;
}
}

And then my Manifest:

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".FeedbackMain"
        android:label="@string/title_activity_feedback_main" >
    </activity>

However, I am getting red lines under .FeedbackMain and the error message is:

.FeedbackMain is not assignable to 'android.app.Activity'

I was wondering why is it so? It was working fine with Android development tools but then when I switched to Android Studio, this happens.

Thanks in advance.

Edit

xml file for mainActivity:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />

style.xml:

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
</style>

</resources>

QWERTY almost 9 years

But when I removed it, it tells me null pointer exception at this line: actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
QWERTY almost 9 years

But when I removed it, it tells me null pointer exception at this line: actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
QWERTY almost 9 years

I tried to changed it just now but it still crashed
AlexWalterbos almost 9 years

So actionBar is null, which means getActionBar() returns null. Can you add the layout xml file of your fragment and activity to your post?
Jorgesys almost 9 years

ok Denise you want to use it as a fragment delete the declaration inside the AndroidManifest.xml and keep extending as a Fragment.
QWERTY almost 9 years

Yeah I deleted already but then it gives me an error message of null pointer exception at actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Bidhan almost 9 years

Add getWindow().requestFeature(Window.FEATURE_ACTION_BAR); before setContentView(R.layout.activity_main) inside your MainActivity.java and see if it works.
QWERTY almost 9 years

I edited the post already. Basically the fragment layout is just linear layout with a lot of textview
AlexWalterbos almost 9 years

Checkout this tutorial on setting up the ActionBar. Your activity need to extend ActionBarActivity, for example. This tutorial (and the next steps) should help you out.
Bidhan almost 9 years

Alright, go inside your res>values folder and post the styles.xml file here.
Jorgesys almost 9 years

thats another issue, in MainActivity add import android.support.v7.app.ActionBarActivity; and extend from ActionBarActivity : public class MainActivity extends ActionBarActivity { use "actionBar = getSupportActionBar();" instead of getActionBar()
QWERTY almost 9 years

After I changed it there is another error message at the ActionBar.TabListener. The error message as Class anonymous class derived from TabListener must either be declared abstrct
QWERTY almost 9 years

Hey any ideas? I am still stuck
QWERTY almost 9 years

After I changed it there is another error message at the ActionBar.TabListener. The error message as Class anonymous class derived from TabListener must either be declared abstract or implement abstract method onTabSelected
QWERTY almost 9 years

Alright but is there any other way to fix this if I wanted to stick with my code?
QWERTY almost 9 years

I have to remove the Override as there are some red line highlighted underneath
AlexWalterbos almost 9 years

You have to remove the ActionBar then.
Durga Mohan almost 9 years

are you using supprort library?
QWERTY almost 9 years

Sorry but how do I check? Is it the one under gradle? dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) compile 'com.android.support:appcompat-v7:22.0.0' }
QWERTY almost 9 years

But I thought without the action bar, there will be no title for the tab?
Durga Mohan almost 9 years

yes, did you import these in your activity? import android.support.v7.app.ActionBar; import android.support.v7.app.ActionBar.Tab;
QWERTY almost 9 years

Yeah these are my imports: import android.support.v7.app.ActionBar; import android.content.Context; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.support.v4.view.ViewPager; import android.support.v7.app.ActionBarActivity; import android.support.v7.app.ActionBar.Tab;
Durga Mohan almost 9 years

also this one import android.support.v7.app.ActionBar.TabListener;
QWERTY almost 9 years

Nope, the same error message still there. Any ideas?
Jorgesys almost 9 years

I can help you Denise, but i think you have more than one issue do you have a link for the complete code?
QWERTY almost 9 years

Let us continue this discussion in chat.
Durga Mohan almost 9 years

Well, i got the error, in you code change android.app.ActionBar.Tab to just Tab like public void onTabReselected(android.app.ActionBar.Tab tab, to public void onTabReselected(Tab tab,
Durga Mohan almost 9 years

Let us continue this discussion in chat.
Jorgesys almost 9 years

Well I have added the methods that you need to implement.